A number of important books have appeared recently defending the institution of marriage. This new volume by family expert Allan Carlson adds to the collection, emphasising, as the subtitle indicates, the public purposes of marriage.

Carlson argues that a number of social, legal and political changes over the past half century have left the institution of marriage reeling from a number of body blows. These include the severing of the connection between marriage and procreation, the introduction of no-fault divorce laws, and the devaluation of the very idea of marriage.

Consider the first radical upheaval. For millennia, as Carlson demonstrates, the idea of marriage was always associated with the idea of procreation. Indeed, that has always been the fundamental purpose of marriage: to produce and protect children.

While other purposes of marriage have existed, the overwhelming rationale for marriage has always been about procreation and raising the next generation.

Of course, we moderns have managed to separate that vital connection, and have reduced marriage to a merely personal affair, with no social, communal or intergenerational concerns. Carlson examines the historical data on this fundamental feature of marriage, and argues that Western civilisation is in large measure formed by this constraint on sexual energy, and the channelling of human sexuality into the confines of marriage and family.

The institution of marriage, says Carlson, is the "foundation of social order and community renewal, universal to human experience". It is the "responsible source of new life; it channels the powerful sexual impulse toward the creation and effective rearing of children".

So important was this cultural and social institution that only recently has the concept of illegitimacy come to be regarded as no longer a matter of concern. Childbearing for millennia was seen as the normal expression of marriage, and illegitimacy was rightly seen as scandalous and shameful.

Now the disconnection between marriage and procreation is all but complete, and thus the very rationale for marriage seems to be eroded as well.

But children still matter, argues Carlson, and marriage is still the best way to ensure the well-being of children. The two-parent family, cemented by marriage, is the best thing we can offer our children.

Not only do children suffer when human sexuality is freed of all boundaries and marriage is transformed into a purely private transaction, but so too do communities. Carlson examines how societies which have rejected marriage big time, such as Sweden, have created a huge range of social problems.

Of course, the issue of same-sex marriage enters the discussion here. If marriage is not seen as a social good and a valuable community institution, then perhaps we should open it up to any and all takers. But Carlson notes that homosexual couples by definition fail to meet the two main criteria of marriage: one man and one woman, and the openness to procreation.

If marriage is a merely private matter, then why stop with same-sex marriage? What about polyamorous groups? What if a bisexual wants the right to marry both a husband and a wife? What is to stop these combinations, if we reject the very nature of marriage?

Included in this short volume is a debate between Carlson and a defender of homosexual marriage, the latter person, interestingly, seeing no real problems with these other permutations.

Decline in fertility

Carlson looks at other issues here: the economic nature of the marriage unit, and the various attempts in history to stamp out marriage and family. He also shows how a decline in marriage leads to a decline in fertility. The Western world is in the midst of a birth dearth, and the move away from marriage is an important factor in this drop in fertility.

He finishes with some proposals for a national marriage policy. Ideas include the reintroduction of "fault" into divorce law, pro-marriage tax policies, and the full legal recognition of marriage as solely that of a man and a woman.

Carlson acknowledges the uphill nature of achieving these proposals, as well as the broader job of reinvigorating the institution of marriage. But he recognises the tremendous value and worth of marriage throughout human history, and the need to champion it against its many enemies.

As such, this is a vital resource in the struggle to protect marriage.